Method for binding bile acids in vivo



United States Patent 3,383,281 METHOD FOR BINDING BILE ACIDS IN ,VIVOFrank J. Wolf, Westfield, N.J., and David M. Tennent,

Ashland, Ohio, assignors to Merck 8: Co., Inc., Rahway, N.J., acorporation of New Jersey No Drawing. Continuation-impart of applicationSer. No. 40,157, July 1, 1960, which is a continuation-in-part ofapplication Ser. No. 748,598, July 15, 1958. This application Sept. 22,1961, Ser. No. 139,879

Claims. (Cl. 167-65) This application is a continuation-in-part of ourcopending application, Serial No. 40,157, filed July 1, 1960, which wasa continuation-in-part of Serial No. 748,598, filed July 15, 1958 bothnow abandoned.

This invention relates to methods and compositions for binding bileacids in the intestinal tract, a process which has two very importanteffects, namely the reduction of blood cholesterol levels in mammals andbirds having hypercholesteremia and the relief of pruritis in patientssuffering from bile stasis.

We have found that bile acids can be effectively bound in the intestinaltracts, and thus placed in a condition to be excreted in a biochemicallyand physiologically inert (i.e., an unabsorba'ble) condition, by theoral administration of non-toxic water insoluble polymeric amines havinga molecular weight greater than 3000, the property of binding at least30% of the available glycocholic acid when exposed to an equal weight ofsaid acid, having a polymer skeleton inert to digestive enzymes, andwhich, after equilibration with air at 100% relative humidity, have amoisture content greater than 68%. Particularly desirable are thenon-toxic quaternary ammonium salts.

Certain ion exchange resins have been reported in the past to have beentested in the binding of ions such as chloride. These resins, however,do not meet the criteria necessary for the binding of bile acids, asdiscussed below.

Heart disease has been the leading cause of death in the United Statesin recent years. Atherosclerosis is one of the most significant forms ofcardiovascular disease because of its frequent occurrence and itspredilection for serious ailments such as coronary thrombosis.Atherosclerosis is characterized by thickening of initima, reduction indiameter, and loss of elasticity of arteries, due to fattyaccumulations. Higher blood levels of cholesterol are observed inatherosclerosis patients than in normal persons. Accordingly, it isconsidered important in the treatment and prevention of atherosclerosisto maintain normal blood cholesterol levels.

The common atherosclerosis therapy up to the present time has been a lowfat diet, devoid as far as possible of animal fats. This necessitatesreduced consumption of nutritious foods such as meat, milk, and eggs. Itis evident that a more desirable therapy would be to permit the patientto have a normal diet and to maintain the cholesterol blood level wheredesired by control with a therapeutic agent. However, prior to thepresent invention no therapeutic agents for maintaining desired bloodlevels of cholesterol which are both safe and effective have been found.

As a result of the present invention it has been found that blood levelsof cholesterol can be maintained at a desired level by the oraladministration of non-toxic glycocholic acid-binding water insolublepolymeric amines having a molecular weight in excess of 3,000 and which,after equilibration with air at 100% relative humidity, have a moisturecontent greater than 65%. Particularly desirable are the non-toxicquaternary ammonium salts which are included within the term polymericamine.

Pruritis, or severe itching, especially at the anus, is a 3,383,281Patented May 14, 1968 major complaint of persons suffering frominterference with normal excretion of bile, as in biliary cirrhosis orother forms of bile stasis. This can be so severe that patients areknown to contemplate suicide. Until recently, the control of suchpruritis has been unsatisfactory, being principally surgical biliarydrainage.

It has now been found that dramatic reduction of the itching associatedwith bile stasis occurs when the bile acids in the gut are bound by themethod of this invention. Further, there is no rise in serum bilirubinnor any adverse effect of the treatment on liver function as measured bystandard tests. The morale of patients is strikingly enhanced. Incertain cases, where the cause of biliary stasis is a blocking of thebile duct, the binding of bile acids in the gut has no effect.

Ability to remove glycocholic acid from aqueous solutions in vitro is agood test of the polymers useful in the present invention. All polymerswhich have been found effective in binding bile acids in vivo arecapable of removing glycocholic acid from aqueous solution in vitro.Polymers which do not remove glycocholic acid from aqueous solution areineffective in vivo. The effective resins bind at least 30% of theglycocholic acid within 5 minutes when a solution of sodium glycocholateis exposed to an equal weight of resin. Glycocholic acid is removed byremoval as a precipitate. The effective insoluble anion exchange resinsremove glycocholic acid as a precipitate, presumably the glycocholateform of the resin.

The surprising correlation between glycocholic acidbinding power invitro, binding of bile acids in vivo, and the ability to reducecholesterol blood levelsin man and other animals apparently can beexplained by the fact that the system maintains a substantially constantbile acid level in spite of the administration of a material whicheffectively removes bile acids from the system. Administration of apolymer according to this invention probably prevents bile acidreadsorption in vivo. Cholesterol is oxidized to bile acids so as tomaintain a substantially constant bile acid level, resulting in alowered cholesterol blood level. This is considered the most probableexplanation of the action of polymers administered according to thisinvention, although we do not wish to be bound by any theory by way ofexplanation.

Why the binding of bile acids in the gut should prove to be such acompetent answer to pruritis is not completely understood since attemptsto correlate the presence of pruritis with the degree of retention ofbile acids in the gut has given equivocable results in the past. A roughcorrelation exists, however, between serum bile acids levels and thepresence or absence of pruritis.

Polymers having a molecular weight of about 3,000 or higher arepreferred in vivo bile acid binding agents. These materials are notabsorbed in the alimentary tract and therefore do not cause toxiceffects. In determining the polymeric amines to use, the importantproperty is their hygroscopy. Peculiarly, only those polymers which,after equilibration with air at relative humidity, have a water contentgreater than 65% are operable in effectively binding bile acids in thegut. Why this hygroscopy should correlate with the ability to bind bileacids is not clear but experimentally it does, just as the binding powercorrelates with reduction of blood cholesterol and relief of pruritis.

The polymeric amines also should have a polymer skeleton (i.e., thefundamental atom chain of the polymer) inert to digestive enzymes. Sincethe latter act usually by hydrolysis, this means that there should be noeasily hydrolyzed amide ester, or similar links in the polymer.Otherwise fragments of too low a molecular weight for effectivesequestration may be formed.

Various polymeric substances have been found to be useful according tothe present invention. They all are polymeric amines having ionizableamino groups, such as amine salt or quaternary ammonium groups (ascontrasted with pseudo amino-nitrogens such as amide groups). One classof useful substances is waterinsoluble synthetic anion-exchange resins,which owe their exchange capacity to amino groups and which have only alow degree of cross-linkage.

One class of effective resins are the Dowex 1 resins, which arepolystyrene resins cross-linked with varying percentages of divinylbenzene, made by Dow Chemical Co., Midland, Mich. Quaternary ammoniumgroups are introduced into such resins by chlormethylation of thearomatic rings and replacement of the chlorine by a tertiary amine suchas trimethyl amine to form, e.g., a trimethyl ammonium group. Thesequaternary ammonium resins are useful in the form of a non-toxic salt,such as the chloride, sulfate, acetate, phosphate, or the like, or inthe hydroxyl form. Any of the Dowex 1 series resins which contain orless of divinyl benzene, as for example Dowex l x 1, Dowex l x 2, andDowex 1 x 4, which contain 1%, 2% and 4%, respectively, of divinylbenzene, are useful. The efiicacy in bile acid binding decreases as thepercentage of cross-linking agent increases. Crosslinkage in excess ofabout 5% seriously impairs the efficacy of these resins. These resinscan be made as described in United States Patent 2,591,573. Otherinsoluble amine salt type resins which are cross-linked to only alimited degree are alse useful in cholesterol blood level reduction. Theabove resins can be further modified in a number of ways. Thequaternizing tertiary amine which is reacted with the ehlormethyl groupcan be any other tertiary amine or cyclic tertiary amine such asdimethylamine ethanol, pyridine, picoline, etc. The extent ofchlormethylation can be varied so that the number of active quaternaryammonium groups per chain is varied. Activity is observed with as low as40% of the theoretically possible active sites. The aromatic ring canhave other substituents such as chlorine or methyl.

Another type of cross-linked amine polymer comprises the polyethyleneimines which have been cross-linked by reaction with a poly functionalhalogen compound, the halogen being displaced by the imine nitrogens inthe chain with loss of the hydrogen. Again here, the amount ofcross-linking must be kept to a minimum.

Other types of cross-linked polymeric amines having ionizable aminogroups will be obvious to those skilled in the resin art. The ability tolower the cholesterol level in the blood and relieve pruritis is afunction of the binding in vivo of bile acids, which is in turndependent on the chemical property of binding glycocholic acid in vitroand the physical property of having a water content of more than 65%after equilibration with 100% relatively humid air. No matter what thestructure, so long as it is a water insoluble polymeric amine withionizable amino groups, a molecular weight of over 3,000, a polymerskeleton inert to digestive enzymes, and has the above properties, itwill be operable.

The minimum effective daily dosage of the useful polymers is about 0.5g./day in man. Because of the low toxicities of the useful polymers,extremely high dosages can be given without ill effect. From thestandpoint of cholesterol serum level reduction or relief of pruritis,no advantages accrue in increasing the daily dosage above 250 g.Preferred dosages lie in the range of about 1 to 100 g./day.

Conventional pharmaceutical formulations of resins according to thepresent invention can be made. In all these formulations it is desirablethat the resin be of a fine particle size, preferably 200 to 400 mesh.The usual pharmaceutical formulations, such as tablets, elixirs, syrups,aqueous solutions, or suspensions and the like, are suitable. The unitdosage is of a convenient size, as for example, tablets from 100 mg. toone gram, or suspensions containing from about 100 mg. to 20 grams ofpolymer.

Examples of various pharmaceutical formulations are as follows:

Formulation 1 Capsules containing a mix of the following ingredients areprepared:

Dowex 1 x 2, anhydrous 500.0 Magnesium stearate 5.0

Net weight 505.0

The resin is mixed with magnesium stearate which serves as a lubricant,and the mixture is filled into No. 0 gelatin capsules.

Formulation 2 A suspension for oral administration is prepared with thefollowing composition:

Dowex l x 2 aqeous suspension (25% The glycerin and tragacanth are mixedand added to 45 ml. of water. The mixture is agitated until homogeneousand heated to about 50 C. The resin is added, followed by the sweeteningagent and water to bring the total volume of the suspension to ml. Thesuspension is agitated and milled.

The sweetening agent specified in this formulation is used in allformulations in this application where a sweetening agent is specified.

Conventional preservatives, flavoring agents, and coloring matter may beadded, if desired, to any of the above formulations. The formulationsfor administering the resins can also be in the form of low caloriediets for treatment of hypercholesteremia in obese patients. Suchcompositions include various food chemicalsvitamins, minerals, fats,proteins, carbohydrates, etc.to form a balanced diet, as well asflavoring agents and dispersing agents. For treatment of pruritis, verylow calorie compositions are usually used.

The resins can also be incorporated in a variety of solid foods such asbread, cookies, cake, cereals, desserts, fruit dishes (e.g., applesauce)and the like. The term orally ingestible carrier in the claims isintended to include such materials as well as the usual pharmaceuticallyacceptable carriers such as capsules, tableting ingredients, syrupcompositions, aqueous solutions and suspensions and the like.

Resins and polymers which are effective in reducing blood cholesterolconcentration are also found to remove glycoeholic acid from aqueoussolutions. Examples 1 and 2 illustrate the removal in vitro ofglycocholic acid from aqueous solution by solid resins.

Example 1 An aqueous solution containing 10 g./liter of sodiumglycocholate was prepared and divided into 25-ml. aliquots. Thissolution was assayed according to the following procedure: An aliquot ofthe solution was diluted to obtain an aliquot estimated to contain 0.1mg. of glycocholic acid in one ml. To this diluted aliquot was added 4ml. of reagent sulfuric acid prepared by diluting 42 ml. of concentratedsulfuric acid with 24 ml. of water. The resulting solution was mixedthoroughly and heated for 15 minutes at 56 C. in a constant temperaturebath. After cooling to room temperature, the optical density wasdetermined at 318 m using the sulfuric acid reagent blank. The opticaldensity of the original solution was obtained by multiplying the opticaldensity of the diluted aliquot TABLE 1 Original Final Percent ResinOptical Optical Removal Density Density Dowex 1 x 2 27. O. 545 98 Dowex1x 4 27. 00 0. 925 96. 5

Since the optical density of sodium glycocholate solutions is directlyproportional to the concentration, the percentage removal of sodiumglycocholate can be calculated from the original and final opticaldensities. As shown in Table 1 Dowex 1 x 2 removed 98% of the sodiumglycocholate from the solution and Dowex 1 x 4 removed 96.5% of thesodium glycocholate. The percentage removal of sodium glycocholate is anapproximate indication of the effectiveness of the resin in vivo,showing that Dowex 1 x 2 is somewhat more effective than the more highlycross-linked Dowex 1 x 4. This was confirmed in in vivo tests.

The effect of various resins on reducing the blood level of cholesterolwas tested in vivo. The results are given in Examples 2, 3 and 4.

Example 2 Male Kerr white leghorn chickens, all nine weeks old, andweighing between 800 g. and 1,000 g., with an average weight of about900 g., were divided into groups of birds each. Two groups served astest groups, and two other groups were used as control groups. All fourgroups received atherogenic diet having the following composition inpercentage by weight:

The vitamin supplements included the following in the amounts indicatedper100 grams of feed:

p-Aminobenzoic acid mg 15.0 Niacin mg 2.0 Calcium pantothenate mg 1.5Pyridoxine mg 0.5 Riboflavin m 0.5 Thiamine mg 0.25 Vitamin A units 4000Vitamin D do 750 Menadione mcg 50 Biotin mcg 12.5 Vitamin B "meg..- 5.0

The average consumption of diet was about 80 grams per bird per day.

The two test groups received, in addition .to the athero genie diet, onepercent by weight (based on the weight of diet) of Dowex 1 x 1 and Dowex1 x 2, respectively, in the chloride form. This amounted to about 800mg. per bird per day based on an average feed consumption of g. per birdper day. After four days the blood plasma cholesterol levels of the fourgroups were found to be as follows:

Mg./ cc. Test group 1 (Dowex 1 x 1) 77 Test group 2 (Dowex 1 x 2) 118Control group A 286 Control group B 269 EXAMPLE 3 Male, Kerr whiteleghorn chickens, all nine weeks old and divided into groups of tenbirds each, were given a basal diet having the following composition:

Percent Yellow corn meal 53.3 Soybean meal 30.0 Fish meal 10.0 Alfalfameal 2.0 Steamed bone meal 2.0 Ground limestone 1.5 Sodium chloride 0.5Choline chloride dry mix (25% choline chloride) 0.4 Manganese sulfate0.02 Inositol 0.05 Vitamin supplements 1 and inerts 0.2

1 Same as in a'therogenic diet in Example 1.

It will be noted that the composition of the basal diet is the same asthat of the atherogenic diet except for the replacement of cottonseedoil and cholesterol with cornmeal.

One test group received in addition to the basal diet 1%, by weight, ofDowex 1 x 2. Two additional groups served as controls. The blood plasmacholesterol concentrations of the test group and the two control groupsafter four days were found to be as follows:

, Mm./ 100 cc. Test group 5 (Dowex 1 x 2) 60 Control group G 79 Controlgroup H 74 EXAMPLE 4 Mg./ 100 cc. Test group 9 (Dowex 1 x 2) 118 Testgroup 10 (Dowex 1 x 2) 176 Average of test groups 9 and 10 147 Controlgroup K (98 birds) 284 The foregoing examples illustrate the substantialreduction of blood cholesterol level in chickens which is achieved bythe administration of a glycocholic acid-binding polymer according tothis invention. Similar results are attained in dogs as shown by theexamples which follow.

EXAMPLE 5 The effect of Dowex 1 x 2 on the blood plasma cholesterollevel of a dog was studied in a test in which the dog was observed firstas a control and then as a test animal. During the control period, whichlasted 51 days, the dog was given a commercial canine diet with nosupplements. A 70-day :test period followed, during which the dogreceived Dowex 1 x 2 in addition to the basal diet received during thecontrol period. The Dowex 1 x 2 was admixed with the diet. The dogreceived 25 7 g. of Dowex 1 x 2 on the first day of the test period, 50g. on the second day, 75 g. on the third day, and 100 g. on the fourthand each succeeding day, except the fifth and sixth days when the dogfasted.

During the control period the blood plasma cholesterol fluctuatedbetween 94 mg./100 cc. and 110 mg./10O cc., and the body weight declinedfrom 18.4 kg. to 17.7 kg. During the test period, the blood plasmacholesterol level fell steadily from 104 mg./100 cc. to 73 mg./100 cc.,showing that Dowex 1 x 2 is effective in lowering blood cholesterollevels. Results are summarized in the following table:

Blood Plasma Cholesterol, Body Weight, Kg. mg. Percent Control period:

Day 1 110 18. 4 94 18. 3 107 18.0 95 17. 9 108 17. 6 103 17. 7

91 70 17.8 test.) 75 1G. 7 73 17.

EXAMPLE 6 A series of polymeric amines was subjected to two tests. Inthe first, the resin was allowed to stand at 100% humidity until it hadbecome equilibrated. The moisture content was then determined. In thesecond, the procedure of Example 3 was followed with each resin. Theresults for those resins having a final moisture content of 65% orgreater after equilibration with 100% humid air are given in Table 2.The results obtained with some resins having less than 65 moisturecontent are given in Table 3. The resins listed in Table 3, although notidentified were mostly chemically similar to those in Table 2 butdiffered in particle size, degree of cross-linking and similar factorsincluding the all important one of hygroscopy. Note that resins 20, 33and 34 are ones whose internal use as gastric neutralizers has beenpreviously described in the prior art.

TABLE 3 Percent Moisture Blood Cholesterol, After Equilibration lug/100Co.

EXAMPLE 7 Patients suffering from jaundice, severe pruritis and highserum bile acid concentrations (15 to 36 ,ug. per ml.) are given g. ofthe resin 2 of Example 6 orally per day. Pruritis ceases in each patientand the serum bile acid concentrations drop markedly. One patient withbiliary cirrhosis, after days of such treatment, has a serum bile acidconcentration of 4.1 ,ug. per ml., having started with 23.7 g. per ml.

When the oral administration of the resin is stopped, bile acidconcentrations increase and pruritis reappears.

EXAMPLE 8 The procedure of Example 1 is followed except that themixtures with resin are well stirred and the bile acid content ismeasured after the times given below in Table 4. The resins used arereferred to by the numbers used in Tables 2 and 3, to facilitatecomparison with the other properties. It is clear from these results andfrom those in Example 6 that, by this test, the resin must bind within 5minutes at least of the glycocholic acid in order to be effective inbinding bile acids in the gut, as shown TABLE 2 Percent Resin MoistureBlood Number Type Special Difl'erenccs after Cholesterol,

Enuilimg./100 cc. bration Dowex 1 x 1 88 84 Dowex 1 x 2 75 86 Dowex 1 x1 acid, latter 68.5 110 polymerized. Dowex 2 x 1, ground to minus4001nesh. 82. 5 108 DOWGX 1 x 0.5 88 148 B-licolinonium salt instead of(CHmN-l- 68 129 Dowex 1 x 2, minus 200 mesh 78 89 Dowex 1 x 2, minus 200mesh, less liy- 75 85 drated. Dowex 1 x 2, minus 200 mesh, still less 7500 hydrated. 10 A Similar to Dowex 1 x 1 but with only so 80 quaternizedsites. 11 B Also quaternized 90. 5 12 A Like Dowex 1 type, but arylrings also 76 104 have CH 13 A Like Dowex 1 type, but aryl rings also 7894 have Cl and some C110. 13 Unquaternized 8G 67 B Unquaternizcd butmore cross-links..- 81 86 13 Quateruized but more cross-links than 801137 Resin types:

(A) Polystyrene cross-linked with divenylbenzene, then chloromethylatcdand the chlorine reacted with amines.

(B) Polyethylene imine, cross-linked.

by secondary results, such as lowering blood cholesterol, even thoughafter much longer times in the in vitro test they show eventually goodsequestration of the glycocholic acid.

TABLE 4 Percent Binding of Glycocholic Acid 5 min. min. 120 min. 240min.

Resin No.:

EXAMPLE 9 The following is an example of a 900-calorie therapeutic dietfor treatment of hypercholesteremia:

Resin #2 of Example 6 (dry) g 10.0 High molecular weight carboxyvinylpolymer (Carbopol 934-B. F. Goodrich Co.) -g 0.42 Sodium alginate g 0.90Corn oil g 20.0 Amorphous silica g 2.5 Non-fat dry milk solids g 150.0Dry malt g 5.0 Sugar powder containing 3% starch g.. 19.8 Sodiumcyclamate g 0.47 Sodium saccharin g 0.12 Cocoa g 24.0 Vanillin (inalcohol) g. 0.1 Methylcellulose g 2.0 Vitamin A Palmitate mg 15.0Vitamin D mg 0.025 Ascorbic acid mg 82.5 Thiamine hydrochloride mg 1.98Riboflavin mg 0.24 Pyridoxine hydrochloride mg 2.48 Oyanocobalamin (0.1%triturated in calcium dibasic phosphate) mgo 5.5 Nicotinamide m-g 1 1.0Calcium pantothenate mg 11.0 Ferrous lactate mg 36.0 Manganous sulfatetetr'ahydrate m-g 7.5 Zinc sulfate heptahydrate mg 22.0

Total g 235.5

The mixture is prepared as follows. The vitamins and minerals arethoroughly mixed. The milk solids, malt, sugar, sodium cycl'amate,saccharin, methylcellulose and cocoa are separately mixed. The vanillinis dissolved in 500 cc. of alcohol and added to the latter mixture,followed by rinsing the container with 250 cc. more alcohol. Thevitamin-mineral mixture is then added and all are thoroughly mixed andcomminuted. The therapeutic resin, carboxyvinyl polymer, and sodiumalginate are then mixed and the corn oil is added. The slurry is stirredwhile the silica is added. The slurry is then added to the powderedmixture previously prepared, comminuted, air dried, and stored inairtight containers.

10 EXAMPLE 10 The following is an example of a -calorie maintenance dosefor treatment of hypercholesteremia:

The vitamin-mineral mixture is the same vitamin-miner'al mixture shownin Example 9 from Vitamin A down, used in the same proportions. Thecomposition is prepared by the same procedure as in Example 9, omittingthe ingredients used there but not called for in the above formula.

EXAMPLE 11 The following is an example of a zero calorie oralcomposition for use in treating pruritis:

Resin #2 from Example 6, dry (adjust actual usage to give this amountreal) g 10.0 High molecular weight carboxyvinyl polymer (Carbopol 934B.F. Goodrich) g 0.42 Sodium alginate g 0.30 Cerelose -g 0.78 Artificialflavoring cc .003

Alcohol as needed Total :g 12.0

The flavoring is dissolved in alcohol and added to the cerelose, thecontainer being rinsed with more alcohol as needed. The resin #2,carboxyvinyl polymer, and sodium alginate are mixed and the flavoredcerelose is added. The mixture is then comminuted, air dried, and storedin airtight packets of 4.0 g. each.

What is claimed is:

1. The method of binding bile acids in the digestive tract into anunabsorba-ble form which comprises administering orally to mammal-s andbirds 0.5 to 250 grams per day of a water insoluble non-toxic polymericamine having a molecular weight in excess of 3,000, having the propertyof binding at least 30% of the available glycocholic acid within 5minutes when exposed to an aqueous solution of an equal weight of saidacid, having a polymer skeleton inert to digestive enzymes, and having awater content greater than 65% after equilibration with air at 100%relative humidity.

2. The method of claim 1 in which the polymer is a quaternary ammoniumsubstituted polystyrene with less than 5% cross-linking.

3. The method of lowering the cholesterol blood level in ahypercholesteremic patient which comprises administering orally tomammals and birds 0.5 to 250 grams per day of a water insolublenon-toxic polymeric amine having a molecular weight in excess of 3,000,having the property of binding at least 30% of the available glycocholicacid within 5 minutes when exposed to an aqueous solution of an equalweight of said acid, having a polymer skeleton inert to digestiveenzymes, and having a water content greater than 65 after equilibrationwit-h air at 100% relative humidity.

4. The method of claim 3 in which the polymeris a quaternary ammoniumsubstituted polystyrene with less than 5% cross-linking.

References Cited UNITED STATES PATENTS Bodamer 26085.l Kohlstaedt 16755McBurney 260-21 Schmitz 16722 12 OTHER REFERENCES ].A.M.A., 151:12,March 21, 1963, pp. 22-23. McChesney, J. Lab. 'and Clin. Med., 39:4,April 1952, pp. 629-636. 5 PSEBM, vol. 84, 1953, pp. 428-431.

Root, J. Lab. and Clin. Med., 42:3, September 1953, pp. 430-437.

ALBERT T. MEYERS, Primary Examiner.

MORRIS o. WOLK, I. IMARCUS, Examiners.

A. P. FAGELSON, Assistant Examiner.

1. THE METHOD OF BINDING BILE ACIDS IN TH DIGESTIVE TRACT INTO ANUNABSORBABLE FORM WHICH COMPRISES ADMINISTERING ORALLY TO MAMMALS ANDBIRDS 0.5 TO 250 GRAMS PER DAY OF A WATER INSOLUBLE NON-TOXIC POLYMERICAMINE HAVING A MOLEUCLAR WEIGHT IN EXCESS OF 3,000, HAVING THE PROPERTYOF BINDING AT LEAST 30% OF THE AVAILABLE GLYCOCHOLIC ACID WITHIN 5MINUTES WHEN EXPOSED TO AN AQUEOUS SOLUTION OF AN EQUAL WEIGHT OF SAIDACID, HAVING A POLYMER SKELETON INERT TO DIGESTIVE ENZYMES, AND HAVING AWATER CONTENT GREATER THAN 65% AFTER EQUILIBRATION WITH AIR AT 100%RELATIVE HUMIDITY.